The Atom code editor has an awesome plugin for pylint: linter-pylint.
For every detected error, linter-pylint produces a tooltip describing the error and giving a link to more complete documentation. Not sure how much work it would be to adopt this to PyCharm and PyTA, but it could be very useful for students.
For example, the examples/pylint/E0211_no_method_argument.py file produces the following:

E0211 🔗 icon points to: http://pylint-messages.wikidot.com/messages:e0211.